The present invention relates to corrugated paperboard containers in general, and to boxes which can be assembled from a glued-up blank without external fasteners in particular.
One of the most economical and versatile containers is the corrugated paperboard box formed from die cut, scored, glued, and folded corrugated sheet stock. The corrugated box is lightweight for its strength, economically produced, compact in its collapsed condition, and ultimately recyclable.
Corrugated containers for producers may be assembled with the aid of automated equipment, tape dispensers, and adhesives. In many applications, however, a corrugated container must be assembled in the field, one at a time, as the need dictates. For consumer applications where the assembly environment is unpredictable, it is preferable that the box be capable of assembly without the need for tools or external adhesive materials.
Corrugated paperboard boxes have been produced, which, although not having an automatic bottom, have strips of gum seal adhesive which are brought together to seal the bottom side flaps to the bottom end flaps. However, some portions of the adhesive strips were positioned to face outwardly where they were readily subject to contamination.
In my U.S. Pat. No. 5,887,782, I disclosed a corrugated container having an automatic bottom which permitted a rapid, convenient, and repeatable opening and closing of a box. This container employed an interior bottom panel which folds down to overlie the scored automatic bottom panel, to present a container with a double thickness bottom.
U.S. Pat. No. 1,936,136, the disclosure of which is incorporated by reference herein, discloses a cardboard box or tray in which end flaps are connected in an erected configuration by an adhesive which adheres only to a like adhesive.
In certain applications, however, even greater strength is required in a container bottom, and for such applications a box which can be assembled without external fasteners or tape and which has a higher strength bottom would be desirable.